In the ‘78-‘79 season they had guys banged up all year. Their leading ppg scorer, Bob McAdoo, only played 20 games for the Celtics that season. They had 18 guys on their roster at various points during the season, in part to deal with the injuries.

Bird’s rookie season, they only had 12 guys play all year and their top 5 scorers all played at least 65 games, four of them 80+. The roster was much more consistent from game-to-game.

When they won it all in ‘81, they upgraded the roster even more with Robert Parish and Kevin McHale.

Bird was fantastic right out the gate, a difference maker, and every bit an all-time great. He deserves a ton of credit. But it was much more than just him that was the difference between a 29-win team and a championship in two years.